Veteran coach Rick Macci, best known for guiding the Williams sisters to tennis stardom, has lauded Coco Gauff’s decision to hire Gavin McMillan as her new coach.
Gauff, who has been struggling with form in recent months, moved after firing one of her coaches, Matt Daly, ahead of the US Open.
Rick Macci Has Explained Why He Thinks Gavin McMillan Is the Best Fit for Coco Gauff
Macci, who often shares his thoughts on tennis through X, recently took to the platform to comment on the latest addition to team Gauff.
“Cori Gauff just made the best decision in his life for Coco,” Macci wrote, lauding the tennis star’s father for bringing Mcmillan on board. According to Macci, the shortcomings in Gauff’s service can be fixed with McMillan’s guidance.
“By hiring Gavin McMillan this can be solved real quick and make her serve click,” said Macci. “What she hears will be 100% different than anything then in the past.”
“He knows the issue and understands joint angles and soft tissue,” Macci said, before going on to describe the move as a “career changer” for the American.
Cori Gauff just made the best decision in his life for Coco. By hiring Gavin Mcmillan this can be solved real quick and make her serve click. What she hears will be 100% different than anything then in the past. He knows the issue and understands joint angles and soft tissue.…
— Rick Macci (@RickMacci) August 20, 2025
McMillan, who claims to have trained hundreds of pro athletes, specializes in improving athleticism, injury prevention, and injury recovery. He has already been spotted with Gauff at the US Open, helping her prepare for the final major of the year.
He also served as Aryna Sabalenka’s biomechanics coach and played a key role in helping her improve her serve.
Initially, Sabalenka struggled with a high number of double faults. But after working with MacMillan, she reduced them and improved her serve’s consistency and power.
Macci Has Previously Pinpointed What Gauff Needs to Fix to Be More Dominant
A few days earlier, Macci called on Gauff to adopt a “science-based plan” to improve her second serve and forehand, which are vulnerable under “extreme pressure.”
“She is at a career crossroad with the 2nd serve and forehand but needs a science based Plan,” Macci wrote on X. “This will not magically go away and bubbles up more under extreme pressure that particular day.”
Macci, a seven-time USPTA National Coach of the Year, has been among Gauff’s biggest supporters and last year claimed she would climb to the top of the rankings. During a recent interview with Tennis365, Macci explained which scientific measures Gauff needed to adopt to become more dominant.
Although Gauff’s wide serve to the deuce court is “one of the best in the world,” she leads the WTA Tour in double faults, Macci pointed out.
“Her racket on her serve, the leg drive doesn’t initiate the racket at the right time and… but keeping her weight back longer with the platform and starting brand new, there’s no doubt that [with] myself and Dr. Gordon (an expert in Biomechanics), this could be solved immediately,” he said.
Earlier this year, Gauff became the first American woman to win the French Open since Serena Williams in 2015. However, she has experienced fluctuating results since her triumph at Roland-Garros.
After a few disappointing results, Gauff appeared to have found form again at the recently concluded Cincinnati Open, where she made the quarterfinals. The 21-year-old American was ousted by No. 7 seed Jasmine Paolini in a tight three-set encounter.
